The nature of the plot, being only 3m wide at the intersection, was a strong determinant in the design form, as was the extensive three-year-long consultation process between the architects and the Conservator Office. The agreed design approach for the plot included the possibility of overhangs at the first level over the two flanking streets – Piekna and Koszykowa.
The strikingly tall and slender form of The Nest derives from an 18th-century urban layout concept called the Stanislawowska Axis. Introduced by King Stanislaw August Poniatowski, the concept is characterised by a series of star-shaped squares and a geometrical grid of streets – some of them intersecting at sharp angles with the squares – resulting in narrow corner plots. During project development, Warsaw’s Metropolitan Monument Conservator Office emphasised that respect be paid to the original urban context and layout. At the same time, it was also their aspiration that the envisaged structure on this important, prominent street corner be as ‘light’ and as much glazed as possible.
Site constraints and design challenges
In the course of the design process further site constraints were imposed on the building form. After an extensive analysis of the utility infrastructure, it was discovered that nearly every municipal utility system crossed the site of the planned development. In particular, telecommunications infrastructure proved particularly problematic as it could not be relocated. As a result, it was necessary to push the ground floor wall a further 6-meters back from the intersection, thus increasing the length of the front overhang from 1.5 m to 7.5 m, with an overall height of just 2.55 m from the pavement. To maintain a vertical clearance at the intersection of the streets, the overhang needed to be appropriately contoured so as not to cause collisions between vehicles turning either into Piekna Street or Koszykowa Street. The front façade above the intersection is, therefore, positioned backwards.
Given the span of the overhangs, a clever structural strategy was required. The weight of the roof overhang is carried by structural columns within the ground floor plan. To support the overhang, a vertical column was used in the corner (a distance of 10-meters from the end of the cantilever) and another column slants from the edge of the ground floor to the top of the overhang. Both the vertical and diagonal columns are bound together by the consecutive floor plates. On the lower floors, reinforced concrete slabs are suspended on steel cables installed in corners of the building.
Composition and form
Compositionally, the glazed overhang is divided into three segments at the 2nd and 3rd-floor levels, respectively. The dark stone core of the staircase spans the building from the ground floor going up to the rooftop. This opaque element provides a striking contrast with the large glazed surfaces.
A glazing concept realised through mock-ups
Construction work went smoothly as the concrete slab floors gradually began to rise. At this point, the first on site mock-ups for the final glazing solution were undertaken to determine the optimal transparency and reflectivity of the glass. The selected glass panels were then installed within an aluminium curtain walling system with the profiles fastened to the perimeter beams of each floor through special hooks made of adjustable steel rods. The even distribution of profiles required a great deal of installation precision as mistakes would result in an uneven façade. For the curtain wall glazing the architects selected a CW 50-HI profile system from Reynaers Aluminium (along with CW 50-HI windows, CS 86-HI doors and CP 155 sliding systems). “To underline the strong features of the design we were aiming to select a system that allows us to choose the finishing of the façade with bigger profiles measuring 27 cm on the intersection and more slender profiles on sides of the building. The final system was a simple semi-structural façade,” project architect Piotr Bzdel says.
In describing the final result, Bzdel says, “Subtle shifts in the glass panels from one to another allow the street onlooker to admire the reflections of the local architecture at different angles. Such an approach to elevation design allows the new building to harmoniously complement its demanding surroundings. The offset glass boxes differ in their external finish, which is particularly visible when looking at the building lit up by the sun from the perspective of the street intersection.” The design of this unique building stands out while fitting in perfectly with its surroundings. With respect for its original local urban layout, this modern office building ensures the intersection remains a prominent one within Warsaw’s city fabric.
Given the importance of creating a building that is as ‘light’ and responsive to its context as possible, the quality of the glazed façade was paramount to the project.